scholarly journals Considerations of the Role of the Cathodic Region in Localized Corrosion

2006 ◽  
Author(s):  
R.G. Kelly ◽  
A. Agarwal ◽  
F. Cui ◽  
X. Shan ◽  
U. Landau ◽  
...  
Keyword(s):  
Localized Corrosion ◽  
Cathodic Region

Localized corrosion in AA2099-T83 aluminum–lithium alloy: The role of intermetallic particles

2015 ◽  
Vol 161 ◽  
pp. 201-210 ◽  
Author(s):  
Y. Ma ◽  
X. Zhou ◽  
W. Huang ◽  
G.E. Thompson ◽  
X. Zhang ◽  
...  
Keyword(s):  
Localized Corrosion ◽  
Lithium Alloy ◽  
Aluminum Lithium Alloy ◽  
Intermetallic Particles ◽  
Aluminum Lithium

The role of Pseudomonas aeruginosa on the localized corrosion of 304 stainless steel

1993 ◽  
Vol 34 (9) ◽  
pp. 1531-1540 ◽  
Author(s):  
J. Morales ◽  
P. Esparza ◽  
S. González ◽  
R. Salvarezza ◽  
M.P. Arévalo
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Stainless Steel ◽  
Localized Corrosion ◽  
304 Stainless Steel

Effect of pH on the Grain Size Dependence of Magnesium Corrosion

CORROSION ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 507-517 ◽  
Author(s):  
K. D. Ralston ◽  
G. Williams ◽  
N. Birbilis
Keyword(s):  
Grain Size ◽  
Corrosion Rate ◽  
Anodic Polarization ◽  
Localized Corrosion ◽  
Anodic Reaction ◽  
Left Behind ◽  
Kinetics Of ◽  
Electrode Technique

Prior works show that grain size can play a role in the corrosion of a metal; however, such works are nominally executed in a single electrolyte/environment at a single pH. In this work, the anodic and cathodic reaction kinetics of pure Mg specimens with grain sizes ranging from approximately 8 μm to 590 μm were compared as a function of pH in 0.1 mol dm−3 sodium chloride (NaCl) electrolytes using anodic polarization experiments and an in situ scanning vibrating electrode technique (SVET). Anodic polarization experiments showed that grain size is important in determining overall electrochemical response, but the environment dictates the form of the grain size vs. corrosion rate relationship (i.e., pH is the overall controlling factor). Consequently, the role of grain size upon corrosion cannot be fully assessed unless a variation in environment is simultaneously studied. For example, the anodic reaction, which dictates active corrosion, also dictates passivation, so the corrosion rate vs. grain size relationship has been shown to “flip” depending on pH. Further, SVET analysis of unpolarized Mg immersed in 0.1 mol dm−3 NaCl electrolyte at neutral pH showed that breakdown of passivity of cast Mg occurred after ~1 h immersion, giving filiform-like corrosion tracks. The front edges of these corrosion features were revealed as intense local anodes, while the remainder of the dark-corroded Mg surface, left behind as the anodes traversed the surface, became cathodically activated. In contrast, grain-refined Mg samples were significantly less susceptible to localized corrosion, and breakdown was not observed for immersion periods of up to 24 h.

scholarly journals Role of Metallurgy in the Localized Corrosion of Carbon Steel

2018 ◽  
Vol 06 (06) ◽  
pp. 618-646 ◽  
Author(s):  
Recep Avci ◽  
Bret H. Davis ◽  
Nathaniel Rieders ◽  
Kilean Lucas ◽  
Manjula Nandasiri ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Localized Corrosion

Clarifying the Role of Mg2Si and Si in Localized Corrosion of Aluminum Alloys by Quasi In Situ Transmission Electron Microscopy

CORROSION ◽  
10.5006/3457 ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 464-475 ◽  
Author(s):  
Shravan K. Kairy ◽  
Nick Birbilis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnesium Silicide ◽  
Localized Corrosion ◽  
In Situ Tem ◽  
Al Alloy ◽  
Transmission Electron ◽  
Al Matrix

The role of magnesium silicide (Mg2Si) and silicon (Si) particles in the localized corrosion of aluminum (Al) alloys was investigated herein. Sub-micrometer-sized Mg2Si and Si particles were grown in the Al matrix of Al-Mg-Si and Al-Si alloys, respectively, and characterized by transmission electron microscopy (TEM). A quasi in situ TEM technique was used to study an identical location containing Mg2Si or Si particle in the Al matrix, prior to and following a period of immersion in 0.1 M NaCl at pH 6, 2, and 12. At pH 6 and 2, Mg2Si was initially “anodic,” preferentially dealloying via selective dissolution of Mg, resulting in the development of SiO-rich remnants that are electrochemically inert. The SiO-rich remnants at pH 2 physically detached from the Al matrix. Silicon particles were electrochemically inert at pH 6, while “cathodic” at pH 2, dissolving the Al matrix at their periphery. It was observed that copper (Cu) was redeposited on Si particles at pH 2. At pH 12, Mg2Si and Si were “cathodic” to the Al matrix. This study clarifies, and provides new insights into, the characteristics of Al alloy physical manifestation of corrosion associated with Mg2Si and Si at the nanoscale.

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